Agent skill

querying-logseq-data

Expert in building Datalog queries for Logseq DB graphs. Auto-invokes when users need help writing Logseq queries, understanding Datalog syntax, optimizing query performance, or working with the Datascript query engine. Covers advanced query patterns, pull syntax, aggregations, and DB-specific query techniques.

View SKILL.md on GitHub Repository
Stars 3
Forks 0

Install this agent skill to your Project

npx add-skill https://github.com/C0ntr0lledCha0s/claude-code-plugin-automations/tree/main/logseq-expert/skills/querying-logseq-data

SKILL.md

Querying Logseq Data

When to Use This Skill

This skill auto-invokes when:

  • User wants to build a Datalog query for Logseq
  • Questions about :find, :where, :in clauses
  • Pull syntax questions (pull ?e [*])
  • Query optimization or performance issues
  • Aggregation queries (count, sum, avg, min, max)
  • Rule definitions or reusable query logic
  • Converting simple query syntax to full Datalog
  • User mentions "Datalog", "query", "datascript" with Logseq context

Reference Material: See {baseDir}/references/query-patterns.md for common query examples.

You are an expert in Datalog queries for Logseq's database-based graphs.

Datalog Query Fundamentals

Basic Query Structure

clojure
[:find ?variable          ; What to return
 :in $ ?input-var         ; Inputs ($ = database)
 :where                   ; Conditions
 [?entity :attribute ?value]]

Find Specifications

clojure
;; Return all matches as tuples
[:find ?title ?author ...]

;; Return as collection (single variable)
[:find [?title ...] ...]

;; Return single value
[:find ?title . ...]

;; Return single tuple
[:find [?title ?author] ...]

;; Pull entity data
[:find (pull ?e [*]) ...]
[:find (pull ?e [:block/title :block/tags]) ...]

Common Query Patterns

Find All Pages

clojure
[:find (pull ?p [*])
 :where
 [?p :block/tags ?t]
 [?t :db/ident :logseq.class/Page]]

Find Blocks with Specific Tag/Class

clojure
[:find (pull ?b [*])
 :where
 [?b :block/tags ?t]
 [?t :block/title "Book"]]

Find by Property Value

clojure
;; Exact match
[:find (pull ?b [*])
 :where
 [?b :user.property/author "Stephen King"]]

;; With variable binding
[:find ?title ?author
 :where
 [?b :block/title ?title]
 [?b :user.property/author ?author]
 [?b :block/tags ?t]
 [?t :block/title "Book"]]

Find Tasks by Status

clojure
[:find (pull ?t [*])
 :where
 [?t :block/tags ?tag]
 [?tag :db/ident :logseq.class/Task]
 [?t :logseq.property/status ?s]
 [?s :block/title "In Progress"]]

Find with Date Ranges

clojure
;; Tasks due this week
[:find (pull ?t [*])
 :in $ ?start ?end
 :where
 [?t :block/tags ?tag]
 [?tag :db/ident :logseq.class/Task]
 [?t :logseq.property/deadline ?d]
 [(>= ?d ?start)]
 [(<= ?d ?end)]]

Advanced Query Techniques

Aggregations

clojure
;; Count books by author
[:find ?author (count ?b)
 :where
 [?b :block/tags ?t]
 [?t :block/title "Book"]
 [?b :user.property/author ?author]]

;; Sum, min, max, avg
[:find (sum ?rating) (avg ?rating) (min ?rating) (max ?rating)
 :where
 [?b :block/tags ?t]
 [?t :block/title "Book"]
 [?b :user.property/rating ?rating]]

Rules (Reusable Query Logic)

clojure
;; Define rules
[[(has-tag ?b ?tag-name)
  [?b :block/tags ?t]
  [?t :block/title ?tag-name]]

 [(is-task ?b)
  [?b :block/tags ?t]
  [?t :db/ident :logseq.class/Task]]]

;; Use rules in query
[:find (pull ?b [*])
 :in $ %
 :where
 (has-tag ?b "Important")
 (is-task ?b)]

Negation

clojure
;; Find books without rating
[:find (pull ?b [*])
 :where
 [?b :block/tags ?t]
 [?t :block/title "Book"]
 (not [?b :user.property/rating _])]

Or Clauses

clojure
;; Find high priority or overdue tasks
[:find (pull ?t [*])
 :in $ ?today
 :where
 [?t :block/tags ?tag]
 [?tag :db/ident :logseq.class/Task]
 (or
   [?t :logseq.property/priority "High"]
   (and
     [?t :logseq.property/deadline ?d]
     [(< ?d ?today)]))]

Recursive Queries

clojure
;; Find all descendants of a block
[[(descendant ?parent ?child)
  [?child :block/parent ?parent]]
 [(descendant ?parent ?child)
  [?child :block/parent ?p]
  (descendant ?parent ?p)]]

[:find (pull ?c [*])
 :in $ % ?root-id
 :where
 [?root :block/uuid ?root-id]
 (descendant ?root ?c)]

Pull Syntax

Selective Attributes

clojure
;; Specific attributes
(pull ?e [:block/title :block/tags])

;; Nested pulling for refs
(pull ?e [:block/title {:block/tags [:block/title]}])

;; All attributes
(pull ?e [*])

;; Limit nested results
(pull ?e [:block/title {:block/children [:block/title] :limit 5}])

Reverse References

clojure
;; Find all blocks referencing this entity
(pull ?e [:block/title {:block/_refs [:block/title]}])

DB-Specific Query Patterns

Working with Classes

clojure
;; Find all classes (tags that are themselves tagged as Tag)
[:find (pull ?c [*])
 :where
 [?c :block/tags ?t]
 [?t :db/ident :logseq.class/Tag]]

;; Find class hierarchy
[:find ?parent-name ?child-name
 :where
 [?child :logseq.property.class/extends ?parent]
 [?child :block/title ?child-name]
 [?parent :block/title ?parent-name]]

Working with Properties

clojure
;; Find all user-defined properties
[:find (pull ?p [*])
 :where
 [?p :block/tags ?t]
 [?t :db/ident :logseq.class/Property]
 [?p :db/ident ?ident]
 [(clojure.string/starts-with? (str ?ident) ":user.property")]]

;; Find property values with type
[:find ?prop-name ?type
 :where
 [?p :block/tags ?t]
 [?t :db/ident :logseq.class/Property]
 [?p :block/title ?prop-name]
 [?p :logseq.property/type ?type]]

Journal Queries

clojure
;; Find all journal pages
[:find (pull ?j [*])
 :where
 [?j :block/tags ?t]
 [?t :db/ident :logseq.class/Journal]]

;; Find journal for specific date
[:find (pull ?j [*])
 :in $ ?date-str
 :where
 [?j :block/tags ?t]
 [?t :db/ident :logseq.class/Journal]
 [?j :block/title ?date-str]]

Query Optimization Tips

  1. Put most selective clauses first - Narrow down results early
  2. Use indexed attributes - :db/ident, :block/uuid are indexed
  3. Avoid wildcards in pull - Specify needed attributes
  4. Use rules for complex logic - Better readability and potential caching
  5. Limit results when possible - Add limits for large datasets
clojure
;; Optimized query example
[:find (pull ?b [:block/title :user.property/rating])
 :in $ ?min-rating
 :where
 ;; Most selective first
 [?b :user.property/rating ?r]
 [(>= ?r ?min-rating)]
 ;; Then filter by tag
 [?b :block/tags ?t]
 [?t :block/title "Book"]]

Logseq Query UI vs Raw Datalog

Simple Query (UI)

{{query (and [[Book]] (property :rating 5))}}

Equivalent Datalog

clojure
[:find (pull ?b [*])
 :where
 [?b :block/tags ?t]
 [?t :block/title "Book"]
 [?b :user.property/rating 5]]

Advanced Query Block

#+BEGIN_QUERY
{:title "5-Star Books"
 :query [:find (pull ?b [*])
         :where
         [?b :block/tags ?t]
         [?t :block/title "Book"]
         [?b :user.property/rating 5]]
 :result-transform (fn [result] (sort-by :block/title result))
 :view (fn [rows] [:ul (for [r rows] [:li (:block/title r)])])}
#+END_QUERY

Common Gotchas

  1. MD vs DB attribute differences

    • MD: :block/content, :block/name
    • DB: :block/title, :block/tags

  2. Property namespacing

    • User properties: :user.property/name
    • System properties: :logseq.property/name

  3. Tag vs Class terminology

    • In UI: "Tags"
    • In schema: "Classes" (:logseq.class/*)

  4. Date handling

    • Dates link to journal pages
    • Compare using date functions, not strings

Recommended Agent Skills

Expand your agent's capabilities with these related and highly-rated skills.

C0ntr0lledCha0s/claude-code-plugin-automations

analyzing-docs

Expert at analyzing documentation quality, coverage, and completeness. Auto-invokes when evaluating documentation health, checking documentation coverage, auditing existing docs, assessing documentation quality metrics, or analyzing how well code is documented. Provides frameworks for measuring documentation effectiveness.

3 0
Explore
C0ntr0lledCha0s/claude-code-plugin-automations

writing-docs

Expert at writing high-quality documentation for code, APIs, and projects. Auto-invokes when generating docstrings, creating README files, writing API documentation, adding code comments, or producing any technical documentation. Provides language-specific templates and best practices for effective documentation writing.

3 0
Explore
C0ntr0lledCha0s/claude-code-plugin-automations

managing-docs

Expert at organizing and managing documentation structure across projects. Auto-invokes when organizing documentation files, setting up documentation frameworks, creating documentation directories, managing doc site configurations, or establishing documentation standards for a project. Provides guidance on documentation architecture and tooling.

3 0
Explore
C0ntr0lledCha0s/claude-code-plugin-automations

Hook Development

This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.

3 0
Explore
C0ntr0lledCha0s/claude-code-plugin-automations

MCP Integration

This skill should be used when the user asks to "add MCP server", "integrate MCP", "configure MCP in plugin", "use .mcp.json", "set up Model Context Protocol", "connect external service", mentions "${CLAUDE_PLUGIN_ROOT} with MCP", or discusses MCP server types (SSE, stdio, HTTP, WebSocket). Provides comprehensive guidance for integrating Model Context Protocol servers into Claude Code plugins for external tool and service integration.

3 0
Explore
C0ntr0lledCha0s/claude-code-plugin-automations

Agent Development

This skill should be used when the user asks to "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "agent tools", "agent colors", "autonomous agent", or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.

3 0
Explore

Didn't find tool you were looking for?

Be as detailed as possible for better results